An anal fissure is a tear in the lining of the anal canal, or a cut or tear in the anus region, that extends into the anal canal. It can result from constipation, anal sex, infections, and other factors.

It can cause pain during and after a bowel movement and there may be blood in the stool.

Most anal fissures are less than one centimeter across, but the anus is a highly sensitive part of the body. As a result, pain in this region can be quite severe, even with a small tear.

In this article, we will cover the symptoms, diagnosis, and treatment of anal fissures, and cover ways in which they can be prevented.

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Here are some key points about anal fissures. More details and supporting information are in the main article.

  • Damage to the lining of the anus is a common cause.
  • They can be idiopathic (no known cause).
  • Approximately 11% of people are affected in their lifetime.
  • Staying hydrated may help prevent anal fissures.

Anal fissures can happen for a number of reasons.

  • Constipation: Large, hard feces (stools) are more likely to result in lesions in the anal area during a bowel movement than soft and smaller ones.
  • Diarrhea: Repeated diarrhea can cause an anal fissure to develop.
  • Muscle spasms: Experts believe that anal sphincter muscle spasms may increase the risk of developing an anal fissure. A spasm is a brief, automatic jerking muscle movement when the muscle can suddenly tighten. Muscle spasms may also undermine the healing process.
  • Pregnancy and childbirth: Pregnant females assigned at birth (FAAB) have a higher chance of developing an anal fissure towards the end of their pregnancy. The lining of the anus may also tear during childbirth.
  • Sexually transmitted infections (STIs): Also known as sexually transmitted diseases (STDs), these are linked to a higher risk of having anal fissures. Examples include syphilis, HIV, HPV (human papillomavirus), herpes, and Chlamydia.
  • Underlying conditions: Some underlying conditions, such as Crohn’s disease, ulcerative colitis, and other inflammatory bowel diseases may cause ulcers to form in the anal area.
  • Anal sex: This can in rare instances cause anal fissures.

Two muscular rings (sphincters) control the anus – the outer ring is consciously controlled; the inner ring is not. The inner sphincter is under constant pressure. Experts believe that, if the pressure gets too much, the inner sphincter might spasm, reducing blood flow, and increasing the risk of a fissure.

The main signs and symptoms of an anal fissure include:

  • Pain: During the passing of a stool, the pain is sharp, and then afterward there may be a longer deep burning sensation. Fear of pain may put some patients off going to the toilet, increasing their risk of constipation. If the person delays using the bathroom, this can make the pain and the tear worse, because the stools will be harder and larger. Some people may experience sharp pain when they clean themselves with toilet paper.
  • Blood: Since the blood is fresh, it will be bright red and may be noticed on the stools or the toilet paper. Anal fissures in infants commonly bleed.
  • Itching: This occurs in the anal area. The sensation may be intermittent or persistent.
  • Dysuria: Discomfort occurs when urinating (less common). Some patients may urinate more frequently.

Anal fissures can affect people of any age or sex equally. It is the most common cause of rectal bleeding in babies and children. Some children may find the sight of bright red blood in stools and toilet paper distressing.

In most cases, anal fissures resolve without the need for medical treatment or surgery. Topical creams, suppositories, or both, and OTC painkillers may help with symptoms. Some people, however, may experience chronic problems if the lesion fails to heal correctly.

An anal fissure that lasts less than 8 weeks is called an acute anal fissure. A chronic anal fissure has symptoms for longer than 8-12 weeks. A primary anal fissure has no identifiable cause, while a secondary anal fissure does have an identifiable cause.

In most cases, an anal fissure will resolve itself within a few weeks. The doctor may recommend some medications to relieve symptoms of pain, burning, or discomfort. If the patient is suffering from constipation, a stool softener may be prescribed.

The individual will also be encouraged to increase their dietary fiber intake, which will help soften the stools. Doctors generally recommend that adults consume 25-30 grams (g) of fiber daily.

There is a risk of stomach cramps, wind, bloating, and diarrhea if the fiber intake increase is rapid and too high.

The increase should be done gradually. The patient should make sure they are drinking plenty of fluids, preferably water.


The doctor may recommend a topical anesthetic. Topical means it is applied directly to the skin. For the prolonged burning sensation after going to the toilet, Tylenol (acetaminophen) or ibuprofen may help (patients should ask their doctors for guidance). Some patients find that a warm (not too hot) bath helps relax the muscles and ease the pain.

Pain relieving medications can be purchased over the counter or online, including ibuprofen and Tylenol.

Topical nitroglycerin medication helps speed up lesion healing by dilating the blood vessels in the area. A doctor may prescribe this medication if healing is slower than expected.

Calcium channel blockers

A medication originally designed to bring down high blood pressure; it also relaxes the sphincter muscle, as well as increasing the supply of blood to the affected area, which speeds up healing.

A steroid cream/ointment

This will reduce inflammation around the lesion, which may help with symptoms of itching and pain.

Botulinum toxin (botox)

Used successfully for many disorders with muscle spasms.


If the fissure is chronic (long-term) and does not heal, surgery may be an option.

A portion of the anal sphincter muscle is surgically removed, resulting in fewer and less severe spasms – this procedure is known as Internal sphincterotomy.

A fissurectomy is the surgical removal of the fissure – this procedure is rare and may be used in children.

Home remedies

To soothe the pain or discomfort at home, a person can try taking a warm sitz bath.

In addition, making sure to drink enough water and eat enough fiber can help the stool soften, so as not to aggravate the fissure further. A person can also consider taking fiber supplements such as psyllium husk.

The following are tips for preventing an anal fissure:

  • Keep stools soft: Eat a well-balanced diet with plenty of fiber. Make sure fluid/liquid intake is adequate – remember that water is the best fluid.
  • Don’t delay using the bathroom: Waiting means that when stools eventually come through, they will be larger and harder.
  • Babies: Frequent diaper changes can reduce the risk of anal fissures developing in babies.
  • “Sharp” foods: Avoid foods that may not be well-digested, such as nuts and popcorn.
  • Wiping: If an individual is susceptible, using moistened cloths or cotton pads to clean after using the bathroom can help. Avoid rough or perfumed toilet paper.
  • Exercise: Regular exercise can reduce the risk of developing constipation, resulting in less risk of anal fissures. Stay well hydrated during and after exercise.
  • Straining: Avoid straining and sitting on the toilet for a long time.

A doctor will usually be able to diagnose an anal fissure after a physical examination of the anal area. If nothing is visible, gentle pressure onto the anal area will often result in pain if there is an anal fissure.

Rectal exam

A rectal exam involves inserting a gloved finger or small instrument into the rectum. Usually, however, the doctor will not do this because it may cause too much pain. A specialist may apply anesthesia to the area before a rectal exam.

If the doctor suspects there may be something more serious, the patient will be referred to a specialist.

Sigmoidoscopy or colonoscopy

A rigid or flexible viewing tube is used to inspect the anus and rectum. This diagnostic test may be ordered if the doctor wants to rule out a more serious disease of the anus.

Do anal fissures go away?

Unless it is chronic, an anal fissure will usually resolve itself within a few days or weeks.

How do you know if you have an anal fissure?

A person experiencing sharp pain, along with bleeding in some cases, while having a bowel movement may have an anal fissure. This pain can be short-term, or it may last for a few hours. It is more likely to a be fissure, if the person is constipated and straining heavily, as this is a common cause.

Do I have a hemorrhoid or fissure?

Rectal bleeding and discomfort can occur with both hemorrhoids and anal fissures. That said, bleeding from the rectum is more likely to be from hemorrhoids than fissures because hemorrhoids develop more often than fissures. In addition, having an external hemorrhoid means the person should feel a bulge in the rectum which is not a sign of a fissure. In either case, an evaluation by a doctor is important.

An anal fissure is a tear or cut in the thin skin of the anus or anal canal, which can be caused by constipation, anal sex, infections, and other factors.

It can result in pain during and after bowel movements and there may be traces of blood in the stool. An anal fissure can be chronic or acute, and medical treatments are available.

However, the best way to prevent it from developing in the first place is by eating enough fiber and staying hydrated.